Screening Among 8 Pathovars of Xanthomonas arboricola pv pruni

Abstract

Xanthan gum is a biopolymer produced by bacteria of the Xanthomonas genus, which is widely used in industry. The potential for xanthan applications highlights the importance of identifying new pathovars of Xanthomonas able to produce xanthan gum with higher productivity and similar or different characteristics, depending on the intended application. This study screened 8 pathovars of Xanthomonas arboricola pv pruni in two different media, MPII and MPI+I. MPII contained (g L⁻¹) sucrose 50.0, K₂HPO₄ 2.5, NH₄H₂PO₄ 1.5, and MgSO₄ 0.1, and MPI + I contained sucrose 50.0, KHPO₄ 5.0, K₂HPO₄ 2.5, NH₄H₂PO₄ 1.5, MgSO₄ 0.3, (NH₄)₂SO₄ 2.0, H₃BO₃ 0.006, FeCl₃ 0.0024, CaCl₂∙2H₂O 0.002, and ZnSO₄ 0.002. Xanthan yields varied from 2.73 g L⁻¹ to 14.53 g L⁻¹ in MPII and 5.83 g L⁻¹ to 22.81 g L⁻¹ in MPI+II. Between these two media, MPI+II showed higher xanthan volumetric yield in all the strains. All the strains achieved higher volumetric yields compared to NRRL B-1459 in both media (p < 0.05) with the exception of strain 76 in MPI+II. All the strains had similar acetyl and pyruvate content. However, a small difference could be observed between the two media. The molecular weight and viscosity were similar to NRRL B-1459. Therefore, all strains have potential industrial applications.